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authorBen Dooks <ben-linux@fluff.org>2006-02-08 21:09:05 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-02-08 21:09:05 +0000
commit2a513ce79958d47b72a11c76ec291c8c1169214c (patch)
tree2698cdc04f710d80da77ed36f6e3aad6d5e9fa57
parentf8e5b28413a8bf0b421dd116b30ab2d3befec629 (diff)
downloadlinux-2.6.34-ux500-2a513ce79958d47b72a11c76ec291c8c1169214c.tar.gz
[ARM] 3303/1: S3C24XX - add clock enable usage counting
Patch from Ben Dooks Move to using an enable count for the shared clocks and protect the clock system using a mutex instead of just disabling IRQs during the clock update. Since there is little more code in the path for non-shared clocks, the enable and disable calls use the same code for each. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mach-s3c2410/clock.c43
-rw-r--r--arch/arm/mach-s3c2410/clock.h1
2 files changed, 34 insertions, 10 deletions
diff --git a/arch/arm/mach-s3c2410/clock.c b/arch/arm/mach-s3c2410/clock.c
index af2f3d52b61..08489efdaf0 100644
--- a/arch/arm/mach-s3c2410/clock.c
+++ b/arch/arm/mach-s3c2410/clock.c
@@ -40,7 +40,6 @@
#include <linux/mutex.h>
#include <asm/hardware.h>
-#include <asm/atomic.h>
#include <asm/irq.h>
#include <asm/io.h>
@@ -59,22 +58,18 @@ static DEFINE_MUTEX(clocks_mutex);
void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
{
unsigned long clkcon;
- unsigned long flags;
-
- local_irq_save(flags);
clkcon = __raw_readl(S3C2410_CLKCON);
- clkcon &= ~clocks;
if (enable)
clkcon |= clocks;
+ else
+ clkcon &= ~clocks;
/* ensure none of the special function bits set */
clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
__raw_writel(clkcon, S3C2410_CLKCON);
-
- local_irq_restore(flags);
}
/* enable and disable calls for use with the clk struct */
@@ -138,16 +133,32 @@ void clk_put(struct clk *clk)
int clk_enable(struct clk *clk)
{
- if (IS_ERR(clk))
+ if (IS_ERR(clk) || clk == NULL)
return -EINVAL;
- return (clk->enable)(clk, 1);
+ clk_enable(clk->parent);
+
+ mutex_lock(&clocks_mutex);
+
+ if ((clk->usage++) == 0)
+ (clk->enable)(clk, 1);
+
+ mutex_unlock(&clocks_mutex);
+ return 0;
}
void clk_disable(struct clk *clk)
{
- if (!IS_ERR(clk))
+ if (IS_ERR(clk) || clk == NULL)
+ return;
+
+ mutex_lock(&clocks_mutex);
+
+ if ((--clk->usage) == 0)
(clk->enable)(clk, 0);
+
+ mutex_unlock(&clocks_mutex);
+ clk_disable(clk->parent);
}
@@ -361,6 +372,14 @@ int s3c24xx_register_clock(struct clk *clk)
if (clk->enable == NULL)
clk->enable = clk_null_enable;
+ /* if this is a standard clock, set the usage state */
+
+ if (clk->ctrlbit) {
+ unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
+
+ clk->usage = (clkcon & clk->ctrlbit) ? 1 : 0;
+ }
+
/* add to the list of available clocks */
mutex_lock(&clocks_mutex);
@@ -402,6 +421,8 @@ int __init s3c24xx_setup_clocks(unsigned long xtal,
* the LCD clock if it is not needed.
*/
+ mutex_lock(&clocks_mutex);
+
s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
@@ -409,6 +430,8 @@ int __init s3c24xx_setup_clocks(unsigned long xtal,
s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
+ mutex_unlock(&clocks_mutex);
+
/* assume uart clocks are correctly setup */
/* register our clocks */
diff --git a/arch/arm/mach-s3c2410/clock.h b/arch/arm/mach-s3c2410/clock.h
index 177d5c8decf..eb5c95d1e7f 100644
--- a/arch/arm/mach-s3c2410/clock.h
+++ b/arch/arm/mach-s3c2410/clock.h
@@ -16,6 +16,7 @@ struct clk {
struct clk *parent;
const char *name;
int id;
+ int usage;
unsigned long rate;
unsigned long ctrlbit;
int (*enable)(struct clk *, int enable);